Chicago -- Grains contracts turned sharply lower on the Chicago Board of Trade Monday following a monthlong downward trend in crude oil.

Corn was off 29 1/4 to off 30, soybeans were off 70 to off 70 3/4, wheat was off 33 1/4 to off 35 1/4 and oats were off 9 to off 9 1/2.

Corn was lower on an expectation of cool weather that should be beneficial to pollination. Wheat prices lowered on increased rain in Argentina and Australia and a trend of strong yields globally. Worries over soybean's late U.S. planting have diminished on fine mid-season weather.

The prices:

Corn: Sep 5.35 1/2, off 29 1/2; Dec 5.55 1/2, off 29 1/2; Mar 5.75 3/4, off 29 1/4; May 5.88, off 30.

Soybeans: Aug 12.87, off 70 3/4; Sep 12.85 1/2, off 70; Nov 12.95, off 70, Jan 13.13, off 70.

Wheat: Sep 7.58 3/4, off 35 1/4; Dec 7.83 3/4, off 35 1/4; Mar 8.07 1/2, off 34 1/4; May 8.21 3/4, off 33 1/4.

Oats: Sep 3.59, off 9; Dec 3.78, off 9 1/2; Mar 3.97 1/2, off 9 1/2; May 4.10 1/2, off 9 1/2.

Copyright 2008 by United Press International.